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Free science diagrams to download

Labelled and unlabelled biology diagrams with printable worksheets and answer keys: plant cell, animal cell, cell membrane, mitochondria, mitosis, meiosis, cell cycle, ear, digestive system, heart, human eye, neuron, microscope, water cycle, photosynthesis, dna structure, bacterial cell, virus. Download SVG, PNG or PDF free under CC BY 4.0, or open any diagram in LabCanvas to edit the colours and labels.

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Labelled plant cell diagram: a box-shaped cell showing the cell wall with plasmodesmata, cell (plasma) membrane, cytoplasm, nucleus with nucleolus and nuclear envelope, rough ER, smooth ER, Golgi apparatus, ribosomes, mitochondrion, peroxisome, chloroplasts with grana, and a large central vacuole bounded by the tonoplast.Plant cell diagramLabelled animal cell diagram: a rounded cell showing the plasma membrane, cytoplasm, nucleus with nucleolus and a nuclear envelope with pores, rough ER, smooth ER, Golgi apparatus, vesicles, mitochondria, lysosome, peroxisome, centrosome with two centrioles, cytoskeleton fibres and ribosomes.Animal cell diagramLabeled diagram of a section of cell membrane (fluid mosaic model) with extracellular fluid above and cytoplasm below. Labels: extracellular fluid, carbohydrate chain, glycoprotein, glycolipid, channel protein, cholesterol, peripheral protein, integral protein, cytoskeleton filaments, cytoplasm, hydrophobic tails, phospholipid bilayer and hydrophilic head.Cell membrane diagramLabeled diagram of a mitochondrion in longitudinal section. Labels: outer membrane, intermembrane space, inner membrane, cristae, ATP synthase, matrix, mitochondrial DNA and ribosomes.Mitochondria diagramLabeled diagram of mitosis in an animal cell with two homologous chromosome pairs (maternal red, paternal blue). Seven cells show interphase (chromatin, nucleolus), prophase (chromosome, centrosome), prometaphase (spindle fibres, nuclear envelope fragments), metaphase (metaphase plate), anaphase, telophase (nuclear envelope, cleavage furrow) and cytokinesis (daughter cells), with an enlarged chromosome showing sister chromatids and the centromere.Mitosis diagramLabeled diagram of meiosis with two homologous chromosome pairs (maternal red, paternal blue). Meiosis I: prophase I (tetrad, crossing over, nuclear envelope), metaphase I (homologous chromosomes on the metaphase plate), anaphase I (spindle fibres, centrosome) and telophase I (cleavage furrow). Meiosis II: prophase II, metaphase II (sister chromatids), anaphase II and telophase II, ending in four haploid daughter cells with swapped chromosome segments.Meiosis diagramLabelled cell cycle diagram drawn as a wheel: interphase with G1 phase, S phase and G2 phase takes most of the circle, and the M phase with mitosis and cytokinesis a smaller arc, with arrows showing the direction. G0 phase branches off G1. Stop signs mark the G1/S checkpoint, G2/M checkpoint and spindle checkpoint. Small sketches show a cell growing, DNA replicating, a cell preparing to divide, chromosomes lined up on the spindle and the cytoplasm dividing.Cell cycle diagramLabelled diagram of the human ear in section, divided into outer ear, middle ear and inner ear. Labels: pinna (auricle), external auditory canal, tympanic membrane (eardrum), malleus, incus, stapes, middle ear cavity, Eustachian tube, oval window, round window, semicircular canals, vestibule, cochlea and vestibulocochlear nerve.Ear diagramLabelled diagram of the human digestive system seen from the front, with the head in side view: mouth, tongue, salivary glands, pharynx, oesophagus, liver, gallbladder, stomach, pancreas, duodenum, small intestine, large intestine (colon), cecum, appendix, rectum and anus.Digestive system diagramLabelled diagram of a human heart in frontal section, seen from the front: superior and inferior vena cava, right atrium, tricuspid valve, right ventricle, chordae tendineae, papillary muscle, pulmonary valve, pulmonary artery, pulmonary veins, left atrium, mitral (bicuspid) valve, left ventricle, interventricular septum, aortic valve and aorta, with blue arrows for deoxygenated blood and red arrows for oxygenated blood.Heart diagramLabelled diagram of the human eye in side section: eyelids lined by the conjunctiva, cornea, anterior chamber filled with aqueous humour, pupil, iris, lens held by suspensory ligaments from the ciliary body, sclera, choroid, retina with the fovea (macula), optic disc (blind spot), optic nerve and the vitreous humour filling the inside of the eyeball.Human eye diagramLabelled diagram of a multipolar motor neuron: branched dendrites around the cell body (soma) with its nucleus, the axon hillock, an axon wrapped in a myelin sheath made by Schwann cells with gaps called nodes of Ranvier, and branched axon terminals ending in synaptic knobs, with an arrow showing the direction of the nerve impulse.Neuron diagramLabelled diagram of a compound light microscope in side view: eyepiece (ocular lens), body tube, arm, coarse focus knob, fine focus knob, base, revolving nosepiece, objective lenses (4x, 10x and 40x), stage clips holding a slide, stage, condenser, iris diaphragm and illuminator, with the light path shown running up through the specimen.Microscope diagramLabelled water cycle diagram: the sun heats the ocean and water vapour rises by evaporation; transpiration rises from trees and sublimation from a snow-capped mountain; condensation forms clouds that the wind carries inland; precipitation falls on the mountains; surface runoff flows to the sea, infiltration soaks down to the water table, groundwater flow returns to the ocean, and collection happens in the ocean.Water cycle diagramLabelled photosynthesis diagram: a chloroplast in cross-section showing the outer membrane, inner membrane, stroma, grana of thylakoids with their lumen, stroma lamellae, chloroplast DNA and ribosomes. Light and water enter the light-dependent reactions on the thylakoids, which release oxygen and pass ATP and NADPH to the Calvin cycle in the stroma; the Calvin cycle takes in carbon dioxide, gives out sugar and returns ADP + Pi and NADP+. The overall equation 6CO2 + 6H2O to C6H12O6 + 6O2 is shown in the corner.Photosynthesis diagramLabelled DNA structure diagram: on the left a right-handed double helix with its sugar-phosphate backbones, base pairs, a nitrogenous base and the major and minor grooves; on the right a flattened ladder section showing phosphates, deoxyribose sugars, the bases adenine, thymine, guanine and cytosine paired A-T and G-C, the hydrogen bonds between them (two for A-T, three for G-C), and the 5' and 3' ends of the antiparallel strands.DNA structure diagramLabelled bacterial cell diagram: a rod-shaped bacterium showing the capsule, cell wall, plasma membrane, cytoplasm, nucleoid (DNA), plasmids, 70S ribosomes, an inclusion body, many short fimbriae, a long pilus and a flagellum anchored in the cell envelope.Bacterial cell diagramLabelled virus diagram in two panels. Left: cross-section of an enveloped virus showing spike glycoproteins, the lipid envelope, a layer of matrix protein, a capsid made of capsomeres and the RNA genome. Right: a bacteriophage showing the head (capsid) containing phage DNA, the tail sheath, the base plate and the tail fibres.Virus diagram

Questions about the diagrams

Are the diagrams free to use?

Yes. Every diagram is free to download and use, including in homework, teaching materials, slides, posters, websites and publications, under the Creative Commons Attribution 4.0 licence (CC BY 4.0). Credit “LabCanvas (labcanvas.com)”.

Which formats can I download?

Each diagram comes as SVG (vector), as a 3200-pixel PNG with a transparent background, labelled and unlabelled, and as a printable A4 worksheet with numbered blanks and an answer key (PDF).

Can I change the labels or colours?

Yes. Click “Edit it in LabCanvas” on a diagram page: it opens in the LabCanvas figure editor as separate shapes and text you can recolour, move and relabel.

Are the diagrams accurate?

They follow the OpenStax Biology 2e and Anatomy and Physiology 2e textbooks, which each page cites. They are simplified teaching illustrations, not drawn to scale.